Rolex Oyster Cosmograph "Daytona", Ref. 6263. Production of this reference started in 1971.Very fine, water-resistant, stainless steel gentleman's wristwatch with round button chronograph,registers, anti-reflection black bezel with tachometer and a Rolex stainless steel Oyster bracelet. three-body, polished and brushed, screwed-down case back, crown and buttons, tachometer graduation onthe black bezel to 200 units per hour. bicolor satiné silver and black with applied steel indexes and tritium-coateddots, auxiliary "guilloché" dials for the seconds, the 12-hour and 30-minute registers. Tritium-coatedsteel "Bâton" hands. Cal. 727, rhodium-plated, 17 jewels, straight line lever escapement, monometallicbalance adjusted to 3 positions, shock-absorber, self-compensating free-sprung Breguet balance-spring,microstella regulating screws.Dial, case and movement signed.Diam. 37 mm.